Have you ever thought the amount of energy wasted in workouts (at gyms and at home) all around the world ?
What if that energy could be used for meaningful purposes other than sweating and keeping fit wealthy and middle class people ?
I wonder if this subject has been discussed in this NG before.
There are simple ways of making a gross estimate of that energy.
Designing ways of storing and converting that energy in useful work is another thing altogether and may be very complex, but... why not give it a try ?
I remember a very long discussion in this NG in the middle 90's about generating energy at home from alternative sources and selling it via the grid. Pitifully it was so long that I after a few weeks I missed the logics of the thread and there was no one to summarize and draw conclusions. I think it drifted to another thread called "The broccoli wars" referring to Reagan´s or Bush, Sr.'s dislike for the broccoli and the habit of their wives serving them as dinner, which was the cause for several wars of the decade.